EP-A-287911 discloses five- or six-component layer products and their use for the production of skis, surfboards and furniture parts. Individually, the layers consist of a film of highly transparent thermoplastic, a polyurethane layer which is tack-free at room temperature, a colour layer, an epoxy resin layer and a support and core material of rigid polyurethane foam, wood or aluminum.
FR-A-2660251 likewise discloses a multilayer system which can be used for skis. It describes inter alia a three-layer system consisting of polycarbonate, polyamide and thermoplastic polyurethane.
A disadvantage of the prior art is that the layer products used to date are insufficiently stable to ultraviolet radiation. For this reason, the layer products are generally provided with a clearcoat layer comprising a special UV absorber system.
The object of the present invention, accordingly, was to develop a layer product which renders superfluous the use of a clearcoat layer comprising a special UV absorber system.
This object is surprisingly achieved by means of a layer product consisting of thermoplastic polyurethane which is stabilized against ultraviolet radiation and is based on diisocyanates, diols as chain extenders, polytetrahydrofuran or linear polyesterdiols.